Submerged rotary type fuel pump



Jan, 29, 19

5 J. w. DICKEY SUBMERGED ROTARY TYPE FUEL PUMP Filed May 7, 1956 4 (3ilm Tmulm'.

ATTORNE 2 United States Patent SUBMERGED ROTARY TYPE FUEL PUMP John W.Dickey, Newfield, N. Y., assignor to Bendix Aviation Corporation, acorporation of Delaware Application May 7, 1956, Serial No. 583,185 4Claims. (Cl. 222-333) The present invention relates to a submergedrotary type fuel pump, and more particularly to an externally driventank mounted pump.

It is an object of the present invention to provide a novel pump of thistype which is a rigid unitary structure, eiiicient in operation and notrequiring fine adjustment.

It is another object to provide such a device which is adapted forcontinuous reliable operation over long periods of time withoutrequiring service or adjustment.

It is another object to provide such a device in which a permanentimpervious closure seals the pump from the motor.

It is another object to provide such a device in which the motor isconnected to the pump by a magnetic coupling in which the spacing andaligning of the magnets is maintained in a simple and effective manner.

Further objects and advantages will be apparent from the followingdescription taken in connection with the accompanying drawing in which:

Fig. 1 is a vertical substantially mid-sectional view of a preferredembodiment of the invention;

Fig. 2 is a section taken on the line 2-2 of Fig. 1;

Fig. 3 is a section taken substantially on the line 3-3 of Fig. 1;

Fig. 4 is a vertical section of the pump structure taken substantiallyon the line 4-4 of Fig. 3;

Fig. 5 is a further detail section of the pump structure taken on theline 5-5 of Fig. 3; and

Fig. 6 is a detail of one of the magnetic coupling discs, the magneticpoles being indicated pictorially.

In Fig. 1 of the drawing there is illustrated a cup shaped casing 1 ofcylindrical form having an intermediate shoulder 2 on which animpervious non-magnetic diaphragm 3 is mounted and hermetically sealedas by means of a soldering operation. A rotary vane type of pumpindicated generally at 1% 18 mounted in any suitable manner on thebottom of the casing 1 with its shaft 4 protruding concentrically intoThe shaft 4 carries a disc-shaped rotor 5 (Fig. 3) having radial slots 6in which rectangular vanes 7 are slidably mounted for cooperation withthe interior of an eccentric pump chamber 8 formed in the pump casing 9.The pump 10 is provided with an inlet 11 (Fig. 5), an outlet 12 (Fig. 2)and a spring loaded by-pass valve connection 13, together with suitableports and passages as indicated more particularly in Figs. 1, 3 and 5,whereby rotation of the pump shaft 4 causes liquid in which the pump isimmersed to enter the inlet 11, and be forced out of the outlet 12.

The upper end of the casing 1 is closed by a mounting plate 14- arrangedto be bolted to the top of a fuel tank 15 as indicated at 16, a gasket17 being interposed to prevent leakage from the tank. A driving motor 18is carried by the mounting plate 14 and attached thereto by bolts andnuts as indicated at 19. The motor shaft 2,779,513 C Fatented Jan. 29,1957 21 extends into the upper chamber of the cup-shaped housing 1 inalignment with the pump shaft 4.

Magnetic means for coupling the motor shaft 21 to the pump shaft 4 isprovided comprising a hollow stub shaft 22 slidably journalled on themotor shaft 21 and connected for rotation therewith by a cross pin 23engaging in slots 24 in the stub shaft 22. A mounting cup 25 is fixedlymounted on the stub shaft 22 and has seated therein a flat ring magnetmember 26 having a series of alternating magnetic poles formed on itssurface as best shown in Fig. 6. It is preferred that this magnet beformed of a material having very high permanent coercive force such asthe materials now available formed of sintered ceramic material, oneform of which is known to the trade by the name of Indox.

The ring magnet 26 is held in the cup 25 by any suitable means as by anouter cup member Zil of non-magnetic material having its rim bentinwardly against a beveled surface of the magnet as shown in Fig. l. Themagnet is maintained in closely spaced relation to the diaphragm 3 bymeans of a thrust bearing 27 for the stub shaft 22, the stationary cup36 of which thrust bearing rests directly on said diaphragm.

A similar permanent magnet 28 is mounted on a hollow stub shaft 29 bymeans of a mounting cup 31. The stub shaft 29 is slidably journalled onthe end of the pump shaft 4 and is connected to rotate with the pumpshaft by a cross pin 32. Magnet 28 is spaced from the diaphragm 3 bymeans of a thrust bearing 33 the stationary cup of which rests againstthe under side of the diaphragm 3. Both the stub shafts 22 and 29 aredrawn toward the diaphragm 3 by the mutual attraction of the twoface-polarized ring magnets 26 and 23.

An outlet fitting comprising a nipple 35 is located in the mountingplate 14 and extends downward through the rim of the casing 1, the jointbeing sealed by the gasket 17. A similar nipple 34 extends upwardly fromthe pump outlet 12 in alignment with the nipple 35 and a hose 36 isarranged to be clamped on the nipples as 3 is then inserted in thecasing and soldered to the shoulder 2 of the casing to form a permanentfluid-tight partition between the upper and lower chambers of thecasing.

The motor 18 is then attached to the mounting plate 14, the drivingcoupling member including the magnet 26 and shaft 22 is slid on themotor shaft 21, the outlet hose 36 is attached to the nipples 34 and 35of the pump and outlet fitting, and the assembly is then inserted in thetank and attached thereto by means of the bolts 16.

Energization of the motor is transmitted through the magnetic couplingto the pump which operates in conventional manner to draw liquid in theinlet 11 of the pump and develop pressure in the outlet 12. The outputof the pump which is in excess of the fuel consumed by the device, suchas an internal combustion engine, to be supplied thereby is permitted toescape back into the fuel tank through the spring pressed relief valve13.

It will be appreciated that since the ring magnets 26 and 28 are merelymaintained in alignment by the motor shaft 21 and pump shaft 4respectively, while their spacing from the diaphragm 3 is maintained bythe thrust bearings 27 and 33 resting directly thereon, the magnets willbe kept in the desired close proximity to each other without thenecessity for close adjustment of either the motor or the pump.

In order to permit circulation of liquid through the lower chamber it ispreferably vented to the fuel tank as 7 indicated at '40. The upperchamber is also'preferably vented to the atmosphere bymeans of slots forthe bolts 19 in the mounting plate 14.

Although but one embodiment of the invention has been shown anddescribed in detail it will be understood that other forms are possibleand changes maybe made in the design and arrangement of the partswithout departing from the spiritof the invention.

1 claim:

1. In a tank-mounted rotary fuel pump, a cup-shaped casing, animpervious non-magnetic diaphragm dividing the casing into upper andlower chambers, a "pump mounted on the bottom 'of the casing having ashaft extending into the lower chamber toward said diaphragm normalthereto, a stub shaft mounted on'the pump shaft and slidablybut'non-rotatably connected thereto, 'a facepolarized disc magnetrigidly mounted on the stub shaft in parallel relation and in proximityto the diaphragm, and a thrust bearing for the stub shaft resting onsaid diaphragm and controlling the spacing of'the disc magnet from thediaphragm; a mounting plate fixed to and closing the upper chamber ofthe casing, ;a motor mounted thereon having a shaft extending into saidupper chamber in alinernent with "the pump shaft, and a face-polarizeddisc magnet mounted on the motor shaft to rotate therewith parallel toand in close proximity to the diaphragm.

2. A tank-mounted fuel pump as set forth in claim 1 including further ahollow stubshaft telescopically splined on the motor shaft, thelatter-mentioned disc magnet being mounted :rigidly on said hollow stubshaft; and a thrust bearing for said stub shaft resting on the diaphragmand controlling the spacing of the .latter-mentioneddisc magnettherefrom.

3. Atank=mountedfuel pump as set forth in claim 1 in which themotorrmounting plateserves-also as a closure for the tank in which thepump is mounted, and said diaphragm is tightly sealed in the casing toprevent passage of liquid from one chamber to the other.

4. A tank-mounted pump as ,set forth in claim v3 in which the lowerchamber is vented into the tank, while the upper chamber is vented tothe. outside of the tank.

No references cited.

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